Fosphenytoin (disodium)

Fosphenytoin (disodium) (CAS No.: 92134-98-0) is a synthetic small molecule and phosphate ester prodrug class research compound, supplied as the disodium salt of fosphenytoin, that is widely used in neuropharmacology and translational drug discovery settings as a controlled precursor to phenytoin for mechanistic studies of neuronal excitability. In biochemical and systems neuroscience contexts, its functional background is defined by rapid conversion in biological matrices by phosphatase mediated hydrolysis to the active moiety phenytoin, which primarily modulates voltage gated sodium channels and limits sustained high frequency action potential firing, thereby supporting experimental interrogation of sodium channel dependent network hyperexcitability pathways. The principal research category is ion channel pharmacology, especially studies focused on neuronal membrane stabilization, seizure like activity modeling, and comparative profiling of sodium channel modulators in central nervous system relevant assays. Consistent with its prodrug nature, direct potency metrics for the parent disodium form are often model dependent and can differ from those of the generated active species, and published in vitro effects in pathway or excitability assays are therefore generally interpreted within nanomolar to micromolar operational ranges for sodium channel related modulation rather than as a single fixed activity constant for the precursor itself. In practical laboratory use, this compound is commonly incorporated into cell based electrophysiology platforms, neuronal culture paradigms, acute slice or network activity assays, and animal models of induced hyperexcitability to benchmark pharmacodynamic response, exposure conversion relationships, and structure activity trends among anticonvulsant chemotypes, while the concentrations or doses used in experiments typically depend on specific experimental designs and research objectives.